Central Bureau Electronic Telegrams, 2946, 2 (2011/December-0)
Supernova 2011ja in NGC 4945 = PSN J13051112-4931270.
MILISAVLJEVIC D., FESEN R., PICKERING T., ROMERO-COLMENERO E., SODEBERG A. and MARGUTTI R.
Abstract (from CDS):
D. Milisavljevic, Harvard-Smithsonian Center for Astrophysics (CfA); R. Fesen, Dartmouth College; T. Pickering and E. Romero-Colmenero, South African Astronomical Observatory and Southern African Large Telescope; and Alicia Soderberg and Raffaella Margutti, CfA, report that low-dispersion spectra (range 350-880 nm), obtained on Dec. 19.1 UT during morning twilight with the 10-m SALT telescope (+ RSS), show PSN J13051112-4931270 = SN 2011ja to be a relatively young type-II supernova. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows a reasonable match to the type-IIP event SN 2004et about a week after maximum light. After removal of the host-galaxy recession velocity of 460 km/s (determined from narrow emission lines), the absorption minimum of the H-alpha line is found to be blueshifted by about -11000 km/s. A suppressed blue continuum and noticeable absorption around Na I are suggestive of significant internal extinction.